How is the nature of the God that Arminians teach sovereign?
The Arminian God is actually more sovereign. For we do not believe He has to have each of us on a short leash to still accomplish His will. Even through the twists and turns of human free will, evil, and everything else, God's will is still accomplished. All without Him having to forcibly steer each and every decision I make. Let that sink in before you start laughing.